Fly.io Made Crystal Clear · chapter 1: What Fly.io Actually Is
Three shapes of compute compared
2026-08-27
A container platform hides the instance from you. A serverless function is built to vanish. A Fly Machine is your process, addressable and yours, until you decide otherwise.
Below: the paragraphs from the book that build this idea, then the diagram itself (Figure 1.1), and a recap. About a minute of reading.
That is the trade Fly.io is selling. A Fly Machine is genuinely yours while it exists: a real process with a real kernel underneath it, addressable by name, not a seat you are borrowing for the duration of one request.
Figure 1.1 puts three shapes of compute side by side, because the confusion Fly.io readers hit most often is not "what is a container" but "which of these three things am I actually renting."
Recap
- The idea: A container platform hides the instance from you.
- The picture: Figure 1.1, from chapter 1 ("What Fly.io Actually Is") of Fly.io Made Crystal Clear.
- Go deeper: the chapter builds this step by step, with recipes and sources at the end.
This diagram is one of many in Fly.io Made Crystal Clear.
Every chapter opens with the gist, draws the hard ideas, and ends with recipes and sources.
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